As medical treatments for HIV have improved, the number of people living with HIV has increased and prevention strategies tailored specifically to people living with HIV have become a priority. We propose to test the efficacy of a client-centered, skills-based intervention that targets a novel mechanism of change: positive affect. High levels of depressive mood are common in people with HIV. Depression, however, is only part of the emotion picture for people living with HIV. Increasing evidence suggests that positive affect plays an important role in adaptation to chronic illness, independent of levels of negative affects like depression. Data from our ongoing study of people newly diagnosed with HIV suggest that positive affect plays an adaptive role in the context of stress and may be the key to more effective interventions for people newly diagnosed with HIV. The proposed research builds on these observational findings to determine whether a 5-session theory- and evidence-based intervention designed to teach skills for increasing the frequency and intensity of daily positive affect does so, and whether this intervention has beneficial effects on subsequent psychological well being, health behaviors, and physical health up to 15 months after diagnosis with HIV. This will be a randomized controlled trial in a sample of 200 participants recruited within 12 weeks of testing positive for HIV. The control group will be attention-matched, and follow up assessments will be conducted immediately post intervention (approximately 5 months post diagnosis) and at 10 and 15 months post diagnosis. The specific aims of the study are to: (1) Determine the efficacy of the Intervention for those Recently Informed of their Seropositive Status (IRISS) for increasing the frequency and intensity of positive affect in men and women newly diagnosed with HIV, during the intervention and at 5- 10- and 15-months after diagnosis;(2) Test the effects of IRISS on HIV-related outcomes - including mental and physical health, coping, and coping resources - and determine whether increases in positive affect are responsible for improvements in these outcomes;(3) Test the effects of the individual theory-based facets of IRISS on positive affect and these HIV-related outcomes;and (4) Evaluate the extent to which personality, socioeconomic status, race/ethnicity, and stress level moderate the effects of IRISS on these outcomes. PUBLIC HEALTH RELEVANCE The first few months after HIV diagnosis provides a window of opportunity for intervention in which patients are establishing new patterns of sexual risk and health behaviors, but there are currently no interventions designed expressly for people newly diagnosed with HIV. There is a need for effective, creative, client-centered interventions that can be easily disseminated to community treatment settings. Given the increasing evidence from our research team and others that positive affect has adaptive functions in the context of health-related stress, we propose to test the efficacy of a positive affect skills-based intervention in people newly diagnosed with HIV.